Core drill



Feb. 7, 1933 C. A. DEAN CORE DRILL Filed May 28, 1930 3mm; CharlesuZDeaw,

Patented Feb. 7, 1933 PAT ENT OFFICE m A. nm, BAIEBSIIELD, CALIFORNIA001m name.

Application filed Kay 28,

drilling have employed a rotary drill such that the core is contained inthe drill barrel.

After removal from'the boring, the core has been extracted either bypushin it from the barrel by a powerful screw or y pumping out the corehydraulically. The first method is exceedingly laborious, while thesecond destroys the full value of the core by .5 leakage of water pastthe hydraulic pusher head. Both require special and powerful equipmentand involve cumbersome manipulation of the heavy drill elements.Moreover, secrecy is difiicult as to the nature of the sam- 2 ple, andthe sample itself often is deformed so' as not to present a correctpicture of the strata being studied. Similar difliculties areencountered by other previous methods, particularly, where a more orless laborious dismantling of the drill has been involved.

An object of this invention is to improve core drilling structures toobtain more simple core retention and extraction; also to obtain a moreeflicient cooperation of parts, so

that the core sample may resent a more accurate picture of the dril ing.Specifically, an improved core-container assemblage is contemplated bythe invention. Also there results a new mode of extracting the core fromthe drill barrel. In particular the invention pertains to an improvedremovable liner for traction more fully set forth herein.

In a specific embodiment, the invention may be illustrated by therovision of a light gage core container. Preferably, this is free torotate easily within the core barrel, yet prevented from being pushedinto the barrel.

Also there is provision torelieve the core from v such pressureas'mightalter the natural con dition of the sample; or impede itsextraction from the barrel. The arrangement further requires only theremoval of a simple key 5 element, for instance'the core cutter proper,

1m. Serial No. 456,686.

to permit easy extraction of the container with the sample concealedagainst unauthorized inspectiom An embodiment of this invention isillustrate'd by the accompanying drawing.

Figure 1 is a vertical section of an assembled drill.

Figure 2 is a horizontal section along the line 22 of Figure 1, throughthe lower part of the drill sub, core barrels and core retainer.

The pilot drill or core cutter proper is designated as 1. Thisisremovably secured to an outer or main barrel 2 of the tool.Preferably, as shown, the cutter is screwed into a collar 3 'while thecollar is threaded to the barrel 2. Threaded externally to the bottom ofthe collar above the cutter 1 there is shown a reamer or hole sizecutter 4. In some forms of the invention the cutter 1 could be threadeddirectly to the reamer 4 but this particular fastening is not theessencev of this invention. An'essential is that by a simple operationthe interior of the drill barrel is exposed so that a separate corecontainer 5 may be inserted and removed. As shown, the pilot cutter inplace serves to hold the container in normal position, and removal ofthe container requires first only that the relatively light pilot drillbe unscrewed from the sub or collar 3.

An inner core barrel 6 preferably is retained within the collar 3 toencircle and protect the'core container. In the particular embodimentillustrated, this inner core barrel is screwed into the collar, and atit's top is provided with a taper seat. the core barrel, and to thecombinations of parts and to the improved art of core ex- The collar 3is of less internal diameter at its lower portion than at the upper,since the upper portion is threaded internally to receive the outer corebarrel. The core cutter 1 is threaded into. the collar so as to providea support for the container 5. Prefer ably an external flange 7, securedto the lower end of the container serves to support the container andalso to limit its up and down ,motion. In the embodiment illustrated theextent of upward motion is determined by the lower end of the inner corebarrel or by' the inner diameter of the collar above the flange, as thecase may be.

The core container need be only of light material, for it is subjectedto very little strain, particularly if combined with other features ofthe invention, to be described.

Tin sheet has been used, and light gage metal in general issatisfactory. In commercial practice the term sheet has an acceptedsignificance to designate. metal below approximately one-eighth of aninch thick. With such material, the container may be split by hand witha small wire retained inside its walls, or by a hatchet or lightmechanical cutter. In some instances a boiler flue is suit-, able. Therange of materials will be a matter of choice, and need not necessarilybe metal; this invention makes possible a satisfactory core container ofless strength than heretofore has been necessary.

Preferably the core container is a single cylinder intact, designed tobe cut or otherwise opened lengthwise when the core finally isinspected. Split or sectional types wit suitable fastening, arepossible, but should be of such construction that no impediment isoffered to the rotatability of the container in the inner core barrelduring drilling, nor to the simple extraction of the container and coreas a whole. Freedom of rotation, absence of jamming, and ease ofextraction, are features of this invention with respect to the coreretainer.

Suitably positioned between the core cutter and the container flanges 7,is an annular element bearing spring prongs 8 to project into thecontainer. In operation the core by pressing back these prongs is heldin a friction grip. In the claims this is designated as a core retainingdevice.

Between the inner and outer core barrels 40 is an annular space 9connected to conduits -1O in the upper tool portions and communicatingbelow with conduits 11 through the sub 3 and preferably also through thereamer blades 4. Thus fluid may be pumped to 4 the cutting members. Inprior practlce the hydraulic pressure of this fluid acted detrimentallyon the core. For this reason the conduits are provided to cooperate withthe upper joint of the inner core barrel in 50 keepin the fluid pressurefrom the upper part 0 the core or core container. In order further torelieve the core or core containerfrom the indirect effects of thehydraulic pressure through entrapped fluid, a conduit 13 through theupper tool portion provides communication between the up er portion ofthe inner core barrel 5 an an upper portion of the drill hole,preferably as shown at approximately such upper level of the inner drillbarrel as is at or above the top of the core on removal, such as throughthe upper drill head.-

, In operation the core as it is cut feeds into the core container andthere is held and protected. The container will provide for such lengthof core as is desired. During the cutting there will be such rotation ofthe cutter dinarily, a new container is inserted and the drillingcontinued after but a minimum loss of time.

Where the container flange is at the bottom it serves further as a meansto grip for removal of the'container, but other conformations preferabltoward the bottom end of the container li ewise will facilitateextraction, and limit vertical play of the container. It will beobserved that in order to avoid crushing of the container there is nopressure imposed downwardly upon its upper positions.

It may be noted that the elements of this drill are simple and maybeassembled or replaced in a simple manner. They are separate so thatparts may be replaced easily, but except the pilot cutter need not beremoved other than for re lacement.

Modifications rom these illustrative embodiments will be within thescope of this invention. For instance features thereof may be utilizedin other than rotary drills. Also the position of the bearing flange maybe altered, and other means to be grasped be provided. Other featureslikewise may be varied within the scope of the appended claims. Theinvention has been set forth in accordance with the patent statutes;what particularly is claimed is r 1. A core. drill having a tubulardrill barrel, and a thin gage core container extending freely andloosely into said barrel and freely withdrawable therefrom with verticalplay limited solely through the conformation of the bottom portionofsaid core container, and a wall surrounding said container to protectit from external pressure upon its own walls.

2. A core drill having inner and outer drill barrels, and a thin gagecore container extending freely and loosely into said inner barrel andfreely withdrawable therefrom with vertical play limited solely throughthe conformation of the bottom portion of said core container.

3. In combination, a core drill having inner and outer drill barrels, athin gage core container extending freely and loosely into said innerbarrel and freely withdrawable therefrom with vertical play limitedsolely by a flange at its bottom,a detachablecore bit supporting saidcore container, and.'acore gripping device retained at the bottom ofsaid core container by means preventing locking engagement between saidcore gripping device and said core bit. is

6 4. In combination a core drill comprising an upper drill head roinwhich depend inner and outer drill barrels embodying a fluid conduithaving communication with the drill ing surfaces, a detachable core bithaving 10 exposed portions to facilitate detachment, a sheet metal corecontainer-extendin freely and loosely into said inner barrel an freelywithdrawable therefrom, said core container having rotary play and beinglimited in '1 vertical play solely by a flange at its bottom that issupported between said detachable core bit and said inner drill barrel,the upper interior-of said cor'e container communicating through saidupper drill head with the exterior of said drill but closed to saidfluid conduit.

5. In a core drill comprising spaced'inner and outer drill barrels and athin gage core container extending freely and loosely into said innerbarrel and freely withdrawable' therefrom with vertical play limitedsolely by a flange at its bottom, a removable collar secured to thebottom of said outer core barrel and having an annular conduitcommunieating with the space between said inner and outer drill barrels,reamer blades detachably secured to said collar and having spaced con'duits communicating with said annular con- 7 duit, and a detachablepilot drill secured to said collar to .support said core containerflange and having portions extending below said reamer blades tofacilitate detachment of said pilot drill and to prevent washing of thecore by fluid flowing from said reamer blades. a

In witness whereof I aflix my signature.

CHARLES A. 4

